Production of ethylene glycol.



UNITED STATES PATENT OFFICE.

ARTHUR HOUGH, or LAVIGN oUEiano, CANADA.

PRODUCTION OF'E'IHYLENE GLYCOL.

No Drawing.

To all whom it may concern:

Be it known that I, ARTHUR HOUGH, a subject of the King of Great Britain, and a resident of Lavigne, Province of Quebec, Canada, have invented certain new and useful Improvements Relating to the Production of Ethylene Glycol, of which the following is a specification.

My invention relates to the manufacture of ethylene glycol and has for its object the production of this compound by a novel process which is characterized by simplicity and cheapness of operation and which in its specific form, as hereinafter described, is cyclic in nature and results in the production of glycol without the formation of byproducts.

The process of this invention utilizes ethyl alcohol as astarting material and consists, broadly considered, in dehydrating this ma terial, thus forming ethylene, then forming an ethylene halid by suitably combining the ethylene with a halogen, and then replacing the halogen of the ethylene halid by a hydroxyl group with the production of ethylene glycol.

The dehydration of ethyl alcohol is preferably accomplished by the following process which constitutes a distinct feature of the present invention: Ethyl alcohol, which may be of any strength without in the least affecting the yield of ethylene obtained from the unit of alcohol represented, is vaporized and its vapor is passed at an elevated temperature in contact with a suitable substance, such as aluminum sulfate, which will under these conditions dehydrate the alcohol. This substance is preferably finely divided and is distributed'upon a neutral material in which case it forms a thin layer around each unit of the carrying material. The neutral carrier may consist of material such as pumice or asbestos and when coated may be placed within tubes through a battery of which the vapor is conducted. The aluminum sulfate within the tubes is maintained at a temperature above 300 C, preferably from 350 C to 400 C. The action between the vapor and the aluminum salt is evidently catalytic. At any rate the alcohol is dehydrated, the ethylene issuing entirely pureand the water being caught in a suitable condenser located at the end of the battery. The contact material is apparently unchanged as a result of the action and being permanent, requires no attention Specification of Letters Patent.

Patented Nov. 28, 1916.

Application filed February 21, 1914. Serial No. 820,336.

beyond the maintenance of the, requisite temperature.

It is notable in connection with the process of dehydration that the presence of denaturants in the alcohol, such as bone oil and aldehyde, does not interfere in the slightest degree with the process. It is also characteristic of this process that no byproducts are formed, such as ether, aldehyde or other decomposition products of ethyl alcohol. Furthermore the process is capable of removing all of the water so that a substantially theoretical yield of ethylene is produced from the alcohol; and this is true irrespective of the degree of dilution of the alcohol. In this respect particularly my hydration is superior, to dehydration by means of phosphoric acid or other dehydrating substances, which produce incomplete yields; and it is superior furthermore in that while my contact agent requires no attention, dehydrating agents employed heretofore must necessarily undergo treatments to preserve'their activity.

The ethylene produced by the dehydration is now combined in any suitable and wellknown manner with chlorin or its equivalent with the formation of ethylene dichlorid. The dichlorid is then treated with water and a suitable oxid, preferably ferric oxid, under high pressure in a suitable apparatus, as, 'for instance, an autoclave. this process ethylene glycol and ferric chlorid are produced. The ferric chlorid is now separated in any desired manner from the ethylene glycol and then heated with the formation of ferric oxid and chlorin. The oxid and the chlorin are now utilized in a repetition of the above process for the production of further quantities of ethylene glycol.

I prefer to use ferric oxid in the above process because it is readily converted into the chlorid, and again upon the application of heat it takes up oxygen and is completely resolved into ferric oxid with the evolution of chlorin in almost quantitative yields. This oxid, moreover, has the highest heat of formation into the chlorid and is of particular value because the simple application of heat to its chlorid results in the giving off of all the chlorin. In this process no by-products are formed but the process is a continuous one, requiring for such operation only the continuous supply of ethyl alcohol.

The process, it will be observed, is a cyclic one, the chlorin used in the formation of ethylene chlorid being recovered later and used over again; the iron oxid used to decompose the ethylene chlorid and convert it into ethylene glycol is also recovered later and used over again.

I claim:

1. In the process of producing ethylene compounds that improvement which cow sists in passing ethyl alcohol vapor in contact with thin layers of aluminum sulfate carried upon neutral material, under exclusion of air and at a temperature in the. aluminum sulfate of about 350H)0 C.

2. The process of producing ethylene glycol which consists in removing all combined oxygen from ethyl alcohol vapor without forming aldehydes by passing said vapor in contact with thin layers of aluminum sulfate carried upon neutral material, under exclusion of air and at an elevated temperature, combining the freshly produced product (ethylene) with chlorin to form ethylene dichlorid and then replacing the chlorin of the ethylene dichlorid with a hydroxyl group.

3. The process of producing ethylene glycol which consists in removing all combined oxygen from ethyl alcohol vapor without forming aldehydes by passing said vapor in contact with thin layers of aluminum sulfate carried upon neutral material, under exclusion of air and at an elevated temperature, converting the freshly produced ethylene into ethylene diohlorid and then converting the dichlorid into ethylene glycol.

l. The process of producing ethylene glycol which consists (l) in removing all combined oxygen from ethyl alcohol vapor without forming aldehydes by passing said vapor in contact with thin layers of aluminum sulfate carried upon neutral material, under exclusion of air and at an elevated temperature combining the freshly produced product (ethylene) with chlorin to form ethylene dichlorid (3) then replacing the chlorin of the. ethylene dichlorid with a hydroxyl group by means of ferric oxid (l) oxidizing the ferric chlorid thus produced to obtain ferric oxid and chlorin and (5) then returning the oxid and chlorin thus obtained to the third and second stages of the process respectively.

In testimony whereof, I have hereunto set my hand in the presence of two subscribing witnesses.

ARTHUR HOUGH. \Vitnesses S. S. BAILEY, G. \VIIITESIDE. 

